JP4669734B2 - Electric motor rotor, electric motor and washing machine - Google Patents

Description

  The present invention relates to a rotor of an electric motor used for a washing machine or the like, an electric motor including the rotor, and a washing machine including the electric motor.

As an electric motor generally used in a washing machine or the like, there is a brushless electric motor. An example of this brushless motor is disclosed in Patent Document 1 below. It is also known to use a rare earth magnet for the magnet of this brushless electric motor.
JP 2000-78787 A

  The rotor of this type of motor includes a rotor core, a plurality of permanent magnet pieces provided on the outer periphery of the iron core, a synthetic resin portion molded integrally so as to embed the rotor core and the permanent magnet pieces, It is comprised. Here, the rotor core is formed by laminating electromagnetic steel plates, and permanent magnet pieces made of rare earth are embedded in a plurality of embedded grooves formed along the rotation direction.

  At the time of molding, the rotor core embedded with the permanent magnet pieces is placed in a molding die, and in this state, a synthetic resin material is injected into the die to perform molding. In this case, a support pin is provided in the mold so that the rotor core and the permanent magnet piece are held at a predetermined position, and the rotor core and the permanent magnet piece are pressed into the mold with the support pin. Synthetic resin material is injected.

  Since this support pin is removed after molding, the synthetic resin portion is formed with a punch hole that is a trace of the support pin, and the permanent magnet piece in the synthetic resin portion is partially formed from this punch hole. Will be exposed. For this reason, the permanent magnet piece exposed from the punched hole is rusted, which is a cause of impairing the performance of the electric motor. In order to avoid this problem, there is a method of using a permanent magnet piece whose surface is subjected to rust prevention treatment, but in this case, there is a problem that the cost is greatly increased.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a rotor that eliminates the exposure of permanent magnet pieces from the punched holes and does not impair the performance of the electric motor.

In order to achieve the above object, the present invention provides:
A rotor core formed by laminating electromagnetic steel sheets, a permanent magnet piece made of a rare earth embedded in a plurality of embedded grooves formed in the rotor core along the rotation direction, the rotor core and the rotor core A synthetic resin portion integrally molded so as to embed a permanent magnet piece, and the synthetic resin portion is a punch that is a trace of a support pin for holding the rotor core during molding In the rotor of the motor in which the hole is formed,
On one surface of the rotor core, a pressing member that closes the embedded groove hole and presses the permanent magnet piece is provided, and at the time of molding, the pressing member abuts on the support pin to hold the rotor core. In this manner, after pressing, the pressing member is exposed from the punched hole.

  The rotor of the electric motor of the present invention configured as described above is provided with a pressing member that presses the permanent magnet piece on the rotor core, and the pressing member is exposed from the punched hole. Since it is not exposed, rusting of the permanent magnet piece can be effectively suppressed. As a result, a long-life motor can be provided without impairing the performance of the motor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, the configuration of an electric motor to which the present invention is applied will be briefly described with reference to FIG. The electric motor 30 includes a rotor 1 coupled to a rotating shaft 34 and a stator 32 fixedly disposed so as to face the outer peripheral surface of the rotor 1. The rotor 1 incorporates a rotor core 2 in which a plurality of permanent magnet pieces 3 are embedded along the direction of rotation, while an electromagnetic coil 32a is wound around the stator 32. The rotor 1 is rotated with respect to the stator 32 by electromagnetic action between the permanent magnet piece 3 of the rotor 1 and the rotating shaft 34 is rotationally driven integrally therewith.
The present invention relates to the structure of the rotor 1 used for such an electric motor 30.

  As shown in FIGS. 1 and 2, the rotor 1 of this example includes a rotor core 2, a permanent magnet piece 3, a rotating shaft support plate 4, a pressing member 5, a position detection sensor magnet 6, a sensor magnet support member 7, A synthetic resin portion 8 is provided. Here, the rotor core 2, the permanent magnet piece 3, the rotating shaft support plate 4, the pressing member 5, the position detection sensor magnet 6, and the sensor magnet support member 7 are integrated with the synthetic resin portion 8 so as to be embedded in the synthetic resin portion 8. The rotor 1 is formed by molding. The rotor 1 also has a plurality of cooling fan protrusions 9 protruding from the end face of the synthetic resin portion 8 in the direction of the rotational axis. Further, the synthetic resin portion 8 of the rotor 1 has a working hole 22 for inserting a jig when the rotor 1 is assembled to the electric motor, and the inner peripheral surface of the synthetic resin portion 8 has an electric motor. Ribs 23 are formed to be pulled out with a jig when the rotor 1 is removed from.

  The rotor core 2 is formed by laminating a plurality of electromagnetic steel plates as shown in FIGS. Here, three types of electromagnetic steel plates as shown in FIGS. 8, 9, and 10 are used as the electromagnetic steel plates constituting the rotor core 2. That is, an electromagnetic steel plate (FIG. 8) as a pressing member 5 provided on one side of the rotor core 2 and an electromagnetic steel plate 10 (FIG. 9) that is positioned adjacent to the pressing member 5 and that corresponds to the rotating shaft support plate 4. ) And a magnetic steel sheet 11 (FIG. 10) as a main part occupying most of the rotor core, the rotor core 2 is configured.

  One electromagnetic steel plate is sufficient as the pressing member 5, but a plurality of magnetic steel plates may be used. The electromagnetic steel plate 10 corresponding to the rotating shaft support plate 4 requires a plurality of sheets because a large force is applied in connection with the rotating shaft support plate 4. Other portions of the rotary shaft core 2 are occupied by a large number of electromagnetic steel sheets 11.

  The electromagnetic steel plate 10 corresponding to the rotating shaft support plate 4 and the magnetic steel plate 11 as the main part are formed in the same shape on the outer peripheral side. The inner peripheral side of the electromagnetic steel plate 11 has a large-diameter circle, and the inner peripheral side of the electromagnetic steel plate 10 is smaller than the inner diameter of the electromagnetic steel plate 11 and has irregularities. The electromagnetic steel sheet as the pressing member 5 has the same irregularities on the inner peripheral side as the inner peripheral side of the electromagnetic steel sheet 10, and the outer periphery is formed smaller in diameter than the outer periphery of the electromagnetic steel sheet 10.

  The electromagnetic steel plate 10 and the electromagnetic steel plate 11 have embedded groove holes 20 for embedding a plurality of permanent magnet pieces 3 along the rotation direction of the rotor. The embedded groove 20 is provided at a position near the inner periphery of the rotor magnetic pole portion formed in a convex shape on the outer periphery of the rotor 1, and is substantially perpendicular to the radial line passing through the rotation axis of the rotor core 2. It is formed in an elongated rectangular shape that intersects. Since the electromagnetic steel plate 10 and the electromagnetic steel plate 11 having the embedded groove hole 20 are stacked to form the rotor core 2, the embedded groove hole 20 as the entire rotor core rotates along the rotational axis of the rotor core 2. It is formed so as to penetrate the core 2.

  As shown in FIG. 12, the rotor core 2 formed by stacking the electromagnetic steel plates 10 and 11 and the electromagnetic steel plates as the pressing members 5 is integrally formed by combining the coupling punches 24 formed on the respective electromagnetic steel plates. Become a rotor core. Thus, by integrating the rotor core 2, the electromagnetic steel sheet does not fall apart and is easy to handle. The rotor core is molded so as to be embedded in the synthetic resin portion, but is strong because it is integrated in advance.

  The embedded groove hole 20 is formed so as to penetrate the rotor core 2 along the rotation axis and open to both side surfaces, and one side thereof is partially blocked by the pressing member 5. Here, the pressing member 5 is provided so as to close the inner diameter side half of the embedded groove hole 20.

  The permanent magnet piece 3 has a flat plate shape as shown in FIGS. 3 and 4, and is magnetized with N and S poles so that the plate thickness is divided in half. The permanent magnet piece 3 is embedded in the embedded groove 20 so that the poles are aligned inward and outward along a radial line passing through the rotational axis of the rotor core 2. In FIG. 3, the permanent magnet piece 3 is embedded so that the S pole is located on the inner circumference side and the N pole is located on the outer circumference side. Here, the plurality of permanent magnet pieces 3 are arranged so that the arrangement of the magnetic poles is reversed between adjacent ones.

  The permanent magnet piece 3 inserted into the embedded groove hole 20 abuts on the pressing member 5 and is positioned and held in the embedded groove hole 20 so as to be pressed by the pressing member 5. Here, the pressing member 5 is configured to contact only one of the N pole and the S pole (the inner circumferential side) so as to press the permanent magnet piece 3, that is, the pressing member 5 straddling the N pole and the S pole. Is not abutted. For this reason, at the end face of the permanent magnet piece 3, the magnetic flux is not short-circuited via the pressing member 5 of the electromagnetic steel plate that easily flows magnetism, and the performance as an electric motor is not impaired.

  The pressing member 5 also serves to hold the permanent magnet piece 3 that fits in the embedded groove hole 20 and to function as an electromagnetic steel plate that constitutes the rotor core 2. In this example, the outer periphery of the pressing member 5 is substantially coincident with the boundary between the N pole and the S pole of the permanent magnet piece 3, but the diameter is smaller than this within a range in which the function of pressing the permanent magnet piece 3 can be maintained. Is possible. Further, the pressing member 5 is not limited to a shape that presses the inner peripheral side from the boundary between the N pole and the S pole, but can be changed to a shape that presses the outer peripheral side.

  The permanent magnet piece 3 is made of a rare earth material. Here, a permanent magnet that has not been rust-proofed and whose surface is not rust-proofed is used. Since the permanent magnet pieces 3 housed in the embedded groove hole 20 are covered with the synthetic resin portion 8 at both end faces, rusting does not easily occur even if the rust prevention treatment is not performed, and the rust prevention treatment-free one can be suitably used. By using the permanent magnet piece 3 that has not been subjected to rust prevention, the cost is reduced. Further, since the rust-proof untreated permanent magnet piece 3 does not have a rust-proof coating, there is little dimensional variation with the embedded groove hole 20 in the dimension size as formed. For this reason, the permanent magnet piece 3 can be easily inserted into the embedded groove hole 20.

  The position detection sensor magnet 6 is supported by a sensor magnet support member 7 as shown in FIG. Since the ring-shaped position detection sensor magnet 6 is fixed to the sensor magnet support member 7 using an adhesive, the position of the rotor 1 is not affected by the position sensor of the electric motor. The rotational position can be detected accurately.

  The sensor magnet support member 7 is formed of a magnetic material (steel plate) through which magnetic flux easily passes, and supports the position detection sensor magnet 6 on a portion opposite to the rotor core 2. For this reason, since the strong field magnetic flux of the permanent magnet piece 3 using rare earth passes through the sensor magnet support member 7 through which the magnetic flux easily passes, the influence of the magnetic flux on the position detection sensor magnet 6 is small.

  As shown in FIG. 11, the sensor magnet support member 7 includes a small-diameter cylindrical portion 7a, an annular flange portion 7b rising from one end of the small-diameter cylindrical portion 7a toward the outer periphery, and a diameter from the outer periphery of the annular flange portion 7b. And a large-diameter cylindrical portion 7c protruding to the opposite side of the small cylindrical portion 7a. As shown in FIG. 2, the sensor magnet support member 7 is supported by fitting a small diameter cylindrical portion 7a to the inner peripheral side of the rotor core 2, and a position detection sensor on the inner peripheral side of the large diameter cylindrical portion 7c. The magnet 6 is fixedly supported. Here, since the small diameter cylindrical portion 7a has a stepped portion 7d having a large diameter between the small diameter cylindrical portion 7a and the annular flange portion 7b, the annular flange portion 7b can be separated from the end surface of the rotor core 2. For this reason, the wraparound of the magnetic flux to the position detection sensor magnet 6 fixed to the inner peripheral side of the large-diameter cylindrical portion 7c can be further reduced.

  The position detection sensor magnet 6 is formed to have an outer diameter such that the outer periphery is inside the boundary between the N pole and the S pole of the permanent magnet piece 3. The position detection sensor magnet 6 is provided with a position corresponding to each permanent magnet piece 3 in the rotation direction, and the magnetic poles arranged in the inner and outer peripheral directions have the same combination. For this reason, if the diameter of the position detection sensor magnet 6 is adjusted to the position of each permanent magnet piece 3, each permanent magnet piece 3 and the position detection sensor magnet 6 may repel and the position detection sensor magnet 6 may be displaced in the rotational direction. There is. Therefore, in this example, the position detection sensor magnet 6 is configured such that the outer periphery is on the inner side of the boundary between the N pole and the S pole of the permanent magnet piece 3, so that the previous repulsion does not occur and the position detection sensor magnet 6 rotates. It is possible to prevent the displacement in the direction.

  As shown in FIG. 2, the rotating shaft support plate 4 is molded and combined with the rotor core 2 by the synthetic resin portion 8. The rotating shaft support plate 4 is formed of a steel plate, and has a coupling hole 4d for coupling with the rotating shaft of the electric motor at the center as shown in FIG. 13, and a recess 4a and protrusions 4b and 4c are formed on the outer periphery. Yes. Here, the convex portions 4b and 4c are formed so as to project symmetrically, and the convex portion 4b is formed so as to project larger than the convex portion 4c.

  On the other hand, the pressing member 5 and the electromagnetic steel plate 10 corresponding to the rotating shaft support plate 4 in the rotor core 2 have irregularities on the inner peripheral side. That is, as shown in FIG. 8, concave portions 5a and convex portions 5b are alternately provided on the inner periphery of the pressing member 5, and similar concave portions 10a and convex portions are also provided on the inner periphery of the electromagnetic steel sheet 10 as shown in FIG. A portion 10b is provided. Here, the concave portion 5a of the pressing member 5, the concave portion 10a of the electromagnetic steel plate 10, the convex portion 5b of the pressing member 5 and the convex portion 10b of the electromagnetic steel plate 10 are formed in the same size and the same shape. As shown in FIG. 6, the concave portions 5 a and 10 a and the convex portions 5 b and 10 b overlap with each other by stacking the electromagnetic steel sheets 10.

  In the synthetic resin part 8, the rotating shaft support plate 4 and the rotor core 2 are combined as shown in FIG. That is, the rotary shaft support plate 4 and the rotor core 2 are combined in a state where the convex portion 4 b of the rotary shaft support plate 4 enters the recesses 5 a and 10 a of the pressing member 5 and the electromagnetic steel plate 10. Since the protrusion 4c of the rotating shaft support plate 4 has a small protruding amount, the protrusion 4c does not enter only by facing the recesses 5a and 10a (the space between the protrusion 4c and the recesses 5a and 10a is not illustrated). 1 is formed).

  The rotor 1 molded integrally by the synthetic resin portion 8 is filled with the synthetic resin between the concave portions 5a and 10a of the rotor core 2 and the convex portions 4b and 4c of the rotating shaft support plate 4, and is strongly bonded. Become a structure. In particular, the portion of the synthetic resin layer filled between the concave portions 5a and 10a of the rotor core 2 and the convex portions 4b of the rotating shaft support plate 4 can only act by compressive force, thus providing a strong coupling structure. it can. Moreover, since the rotating shaft support plate 4 and the rotor core 2 are electrically insulated via the synthetic resin portion 8, the rotor core 2 can be electrically separated from the rotating shaft.

  Molding of the rotor with synthetic resin is performed in a molding die (not shown). In this molding, the rotor core 2 in which the permanent magnet pieces 3 are embedded is set in a mold, and in this state, a synthetic resin material is injected into the mold to perform molding. In this case, a plurality of support pins are provided in the mold so that the rotor core 2 is held at a predetermined position, and the synthetic resin material is placed in the mold in a state where the rotor core 2 is pressed by the support pins. I try to inject. Since the support pins are removed after the molding, as shown in FIGS. 1 and 2, the synthetic resin portion 8 of the rotor 1 is formed with a plurality of punch holes 21 that are traces of the support pins.

  The rotor core 2 set in the molding die is placed in a state in which the support pin is abutted against the pressing member 5, and is a synthetic resin provided on the opposite side (sensor magnet supporting member 7 side) of the pressing member 5. Resin is injected from the injection gate. Here, the rotor core 2 is pushed to the holding member 5 side by the strong injection pressure of the resin. However, the rotor core 2 is securely held at a predetermined position by pressing the holding member 5 against the injection pressure by the support pin. The rotor 1 held and thereby integrally molded with synthetic resin is formed in a predetermined size and shape.

  In the rotor 1 formed in this way, the pressing member 5 is exposed to the outside because there is no resin coating in the portion of the punched hole 21 that is the trace of the support pin. However, since the end surface of the permanent magnet piece 3 is closed from the outside by the pressing member 5, rust is not generated even in the rust-proof untreated permanent magnet piece 3.

  In the rotor 1, since the sensor magnet support member 7 and the position detection sensor magnet 6 are molded and fixed integrally with the rotor core 2 by the synthetic resin portion 8, no fixing member such as a screw is required. Easy to manufacture and assemble.

  FIG. 15 is an enlarged view of a portion where the pressing member 5 presses the permanent magnet piece 3 in the rotor 1 shown in the above embodiment. Here, one side of the S pole or the N pole of the permanent magnet piece 3 is pressed by the holding member 5, and this holding is performed in a range not exceeding the boundary between the S pole and the N pole of the permanent magnet piece 3. Thus, the magnetic flux of the permanent magnet piece 3 is prevented from being short-circuited and flowing.

  Another embodiment of this part is shown in FIGS. In the embodiment shown in FIG. 16, a concave notch 5 f is provided at the center of the tip of the pressing member 5. The notch 5f reduces the range in which the permanent magnet piece 3 is pressed, so that the possibility of short-circuiting the magnetic flux at the end face of the permanent magnet piece 3 is further reduced. In the embodiment shown in FIG. 17, the outer periphery of the pressing member 5 is formed in a circular shape. In this case as well, as in the embodiment of FIG. 16, the range for pressing the permanent magnet piece 3 is reduced. The risk of magnetic flux short circuit at the end face is further reduced.

  FIG. 18 shows another embodiment of the electromagnetic steel sheet constituting the rotor core 2. In this embodiment, a plurality of cut grooves 25 are formed on the outer peripheries of the electromagnetic steel plates 10 and 11. By forming such a cut groove 25, the synthetic resin enters the cut groove 25 in molding, so that the coupling between the rotor core 2 and the synthetic resin portion 8 becomes stronger, and the rotor 1 The mechanical strength of increases.

  FIG. 19 shows another embodiment of the rotor. That is, in the rotor 1 of this embodiment, the rotor core 2 is exposed from the outer peripheral surface of the synthetic resin portion 8, and here the outer peripheral surface of the synthetic resin portion 8 protrudes outside the exposed surface of the rotor core 2. It has a structure. In this case, the step a between the outer peripheral surface of the synthetic resin portion 8 and the exposed surface of the rotor core 2 is about 0.5 mm.

  In this rotor 1, by exposing the rotor core 2 from the outer peripheral surface of the synthetic resin portion 8, electromagnetic efficiency with the stator side is improved, and a more stable rotational force can be obtained. In particular, the rotor 1 has a structure in which the outer peripheral surface of the synthetic resin portion 8 protrudes outward from the exposed surface of the rotor core 2. Therefore, when the rotor 1 is incorporated into an electric motor, the rotor 1 The iron core 2 does not come into contact with the stator and is not completely magnetically attracted, and can be smoothly assembled with a gap between the iron core 2 and the stator.

  FIG. 20 shows a configuration example of an electric motor in which a rotor according to the present invention is incorporated. The electric motor 30 is used for a washing machine, for example, and is unitized with the speed reduction mechanism 31. Here, the electric motor 30 includes the rotor 1, the stator 32, the housing 33, the rotating shaft 34, the end bracket 35, the bearing portion 36, and the position sensor 37 described above. The housing 33 fixes the stator 32 on the inner side, and the rotation shaft 34 is rotatably supported by a bearing portion 36 provided on the end bracket 35, and is coupled to the rotation shaft support plate 4 of the rotor 1. The stator 32 is disposed to face the outer peripheral surface of the rotor 1, and is fixed to the stator 32 by electromagnetic action between the electromagnetic coil 32 a wound around the stator 32 and the permanent magnet piece 3 of the rotor 1. On the other hand, the rotor 1 rotates, and the rotating shaft 34 is rotationally driven integrally therewith.

  The position sensor 37 is disposed so as to face the inner peripheral side of the position detection sensor magnet 6, and detects the rotational position of the rotor 1 by sensing the magnetism of the position detection sensor magnet 6. Here, since the position sensor 37 is located on the inner peripheral side of the position detection sensor magnet 6, the influence of the magnetic flux of the permanent magnet piece 3 on the position sensor 37 is suppressed, and accurate position detection becomes possible.

  The rotating shaft 34 of the electric motor is meshed with the input side of the speed reduction mechanism 31. The input side of the speed reduction mechanism 31 has a planetary gear, and a pinion formed on the rotating shaft 34 is engaged. A washing machine drive shaft 38 is provided on the output side of the speed reduction mechanism 31. The washing machine drive shaft 38 is rotatably supported by the inner bearing 39 of the speed reduction mechanism 31, and the rotation of the rotor 1 is decelerated from the washing machine drive shaft 38 and output. Further, a hollow rotary shaft 40 is provided outside the washing machine drive shaft 38. The hollow rotary shaft 40 is coupled to the case 41 of the speed reduction mechanism 31 and rotates integrally with the rotary shaft 34 to output the rotation of the rotor 1 without decelerating.

  An example of the configuration of a washing machine equipped with such an electric motor is shown in FIG. The washing machine includes a water tank 52 suspended and supported in a housing 50 via a suspension 51, a washing tank 53 that is rotatably arranged in the water tank 52 and into which laundry is put, and the washing tank. 53, and a rotating blade 54 that stirs the laundry in the washing tub 53. In this washing machine, a fixed plate 55 provided at the bottom of the water tub 52 The electric motor 30 shown in 19 is attached.

  The washing machine rotating shaft 38 that is the output shaft of the electric motor 30 is connected to the rotary blade 54, and the hollow rotating shaft 40 is connected to the washing tub 53. Therefore, in this washing machine, at the time of washing, the rotation of the rotor 1 of the electric motor 30 is decelerated via the speed reduction mechanism 31 and transmitted to the rotating blades 54, thereby rotating the rotating blades 54 and washing the laundry in the washing tub 53. A washing operation for stirring is performed, and at the time of dehydration, the rotation of the rotor 1 of the electric motor 30 is transmitted to the washing tub 53 without being decelerated, and the washing tub 53 is rotated at a high speed to perform the dehydration operation. This switching of operation is performed by a clutch mechanism provided in the electric motor.

It is a top view which shows the Example of the rotor of the electric motor by this invention. It is the sectional view on the AA line of FIG. It is an enlarged view of the P section in FIG. It is a perspective view of the permanent magnet piece used for the rotor of an Example. It is sectional drawing of the rotor core in the rotor of an Example. It is the figure which looked at the rotor core of FIG. 5 from the arrow B direction. It is the figure which looked at the rotor core of FIG. 5 from the arrow C direction. It is a top view of the pressing member which comprises a rotor core in the rotor of an Example. It is a top view of the electromagnetic steel plate which comprises a rotor core in the rotor of an Example. It is a top view of the other electromagnetic steel plate which comprises a rotor core in the rotor of an Example. It is sectional drawing of the sensor magnet support member in the rotor of an Example. It is an expanded sectional view of the coupling punch part which couple | bonds the magnetic steel plate laminated | stacked in the rotor of an Example. It is a top view of the rotating shaft support plate in the rotor of an Example. It is a figure which shows the combined structure of the rotating shaft support plate and rotor core in the rotor of an Example. It is an enlarged view of the principal part (portion where the pressing member is pressing the permanent magnet piece) in the rotor of the example. It is an enlarged view which shows the other Example of the principal part. It is an enlarged view which shows other Example of the principal part. It is an enlarged view which shows the other Example of an electromagnetic steel plate. It is an enlarged view which shows the other Example of a rotor. It is sectional drawing which shows the structural example of the electric motor in which the rotor by this invention is integrated. It is a block diagram which shows the example of the washing machine with which the rotor by this invention was integrated and was equipped with the electric motor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Rotor core, 3 ... Permanent magnet piece, 4 ... Rotating shaft support plate, 5 ... Holding member, 6 ... Position detection sensor magnet, 7 ... Sensor magnet support member, 8 ... Synthetic resin part, 10 ... Electromagnetic steel sheet, 11 ... Electromagnetic steel sheet, 20 ... Embedded groove hole, 21 ... Punched hole

Claims (13)

A rotor core formed by laminating electromagnetic steel sheets, a permanent magnet piece made of a rare earth embedded in a plurality of embedded grooves formed in the rotor core along the rotation direction, the rotor core and the rotor core A synthetic resin portion integrally molded so as to embed a permanent magnet piece, and the synthetic resin portion is a punch that is a trace of a support pin for holding the rotor core during molding In the rotor of the motor in which the hole is formed,
On one surface of the rotor core, a pressing member that closes the embedded groove hole and presses the permanent magnet piece is provided, and at the time of molding, the pressing member abuts on the support pin to hold the rotor core. The electric motor rotor is characterized in that after pressing, the pressing member is exposed from the punched hole. In the rotor of the electric motor according to claim 1,
The permanent magnet piece has a flat plate shape, and is magnetized into an N pole and an S pole so as to divide the plate thickness in half, and the pressing member formed of an electromagnetic steel sheet is provided only on one of the N pole or the S pole. A rotor of an electric motor characterized in that the permanent magnet piece is pressed in a contact state. In the rotor of the electric motor according to claim 1 or 2,
An electric motor rotor, wherein the injection side of the synthetic resin at the time of molding is the opposite side to the pressing member. In the rotor of the electric motor according to any one of claims 1 to 3,
The electric steel rotor according to claim 1, wherein the electromagnetic steel sheet has a coupling punch portion that overlaps and couples with each other. In the rotor of the electric motor according to any one of claims 1 to 4,
The permanent magnet piece has a rust-proof untreated surface, and is a rotor for an electric motor. In the rotor of the electric motor according to any one of claims 1 to 5,
The electromagnetic steel sheet has a notch groove formed on an outer periphery thereof. In the rotor of the electric motor according to any one of claims 1 to 6,
A position detection sensor magnet used for position detection of the permanent magnet piece, and a sensor magnet support member that supports the position detection sensor magnet, the sensor magnet support member is formed of a magnetic material that allows easy passage of magnetic flux, A rotor of an electric motor, wherein the sensor magnet is supported on a part opposite to the rotor core. In the rotor of the electric motor according to claim 7,
The sensor magnet support member includes a small-diameter cylindrical portion, an annular flange that rises from one end of the small-diameter cylindrical portion toward the outer periphery, and a large-diameter protruding from the outer periphery of the annular flange to the opposite side of the small-diameter cylindrical portion. A cylindrical portion, and the small-diameter cylindrical portion is fitted on the inner peripheral side of the rotor core, and the position detection sensor magnet is supported on the inner peripheral side of the large-diameter cylindrical portion. Rotor. In the rotor of the electric motor according to claim 7 or 8,
The rotor of an electric motor, wherein the position detection sensor magnet is formed so that an outer periphery thereof is inside a boundary between the N pole and the S pole of the permanent magnet piece. In the rotor of the electric motor according to any one of claims 7 to 9,
An electric motor rotor, wherein the position detection sensor magnet and the sensor magnet support member are molded so as to be embedded in the synthetic resin portion together with the rotor core. In the rotor of the electric motor according to any one of claims 1 to 10,
The synthetic resin portion is further embedded with a rotary shaft support plate for coupling a rotary shaft, the rotary shaft support plate has irregularities on the outer periphery, and the rotor steel core electromagnetic steel plate corresponding to the rotary shaft support plate. In the synthetic resin portion, the rotating shaft support plate and the rotor iron core are combined so that the protrusion of the rotating shaft support plate enters the recess of the electromagnetic steel plate. An electric motor rotor.   An electric motor comprising: the rotor according to any one of claims 1 to 11; and a stator having an electromagnetic coil disposed to face a peripheral surface of the rotor.   An electric motor according to claim 12, a washing tub into which laundry is put, and a rotary blade that stirs the laundry in the laundry tub, wherein the rotation of the rotor is reduced to the rotary blade. A washing machine configured to provide a mechanism for transmitting to the washing tub without reducing the rotation of the rotor.

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